DE102020129293B4 - Method of compiling a cutting plan, method of cutting out and sorting workpieces and flat bed machine tool - Google Patents

Abstract

A method is disclosed for compiling a cutting plan for cutting out a plurality of workpieces from a sheet of material using a cutting beam emerging from a cutting head, wherein an outer contour (27) and optionally one or more inner contours are traversed with the cutting beam to cut out one of the plurality of workpieces will. The method comprises the following steps: - providing a nesting plan (21), which includes an arrangement of the outer contours (27) of the plurality of workpieces on a planning board (25) assigned to the material board, - assigning the outer contours (27) to exactly one of at least four cutting phases (I, II, III, IV), the allocation being made in such a way that two outer contours (27) of a common cutting phase (I, II, III, IV) are not arranged adjacent to one another, with two outer contours (27) facing one another are arranged adjacent if at least two points on one of the two outer contours are each no further away than a predetermined neighboring distance from the other of the two outer contours (27), and- compiling the cutting plan, the cutting plan for each cutting phase (I, II, III , IV) includes the associated outer contours (27), - creating a cutting sequence (23R) for each of the cutting phases (I, II, III, IV) of the cutting plan (2 3) which for each of the cutting phases (I, II, III, IV) comprises a sequence of the outer contours (27) and optionally one or more inner contours (28) belonging to an outer contour (27), - determining a meandering travel path (W) via the planning table (25) for each of the cutting sequences (23R), which determines a movement of a cutting head over a panel-shaped material panel (7), according to which the workpieces (9) of a cutting phase (I, II, III, IV) when processing the cutting plan (23) are cut out one after the other, with each outer contour (27) being surrounded by a collision risk area (K) and the travel path (W) between the outer contours (27) of one of the cutting phases (I, II, III, IV) being determined in such a way that Collision risk areas (K) of outer contours (27) whose associated workpieces (9) have already been cut out in one of the cutting phases (I, II, III, IV) are avoided.

Description

The present invention relates to a flat-bed machine tool for cutting out workpieces from a plate-shaped sheet of material using a cutting beam emerging from a cutting head, and in particular to a method for compiling a cutting plan for controlling a cutting process for cutting out workpieces from a plate-shaped sheet of material and a method for cutting out and Sorting of suitably cut workpieces. Furthermore, the invention relates to a computer program for executing a corresponding method.

Flatbed machine tools, in particular laser cutting or plasma flatbed machine tools, for cutting workpieces out of a material panel using a cutting beam are used in the sheet metal processing industry and typically have a machine area in which the (e.g. laser) processing takes place. Upstream and optionally downstream storage areas for the raw material and/or the cuttings are assigned to the machine area. In the case of flat-bed machine tools, material panels (e.g. sheet metal) to be processed can be fed to the machine area on a pallet, in particular by moving the pallet with the material panel stored thereon into a cutting position in the machine area.

A pallet usually includes an arrangement of support webs on which the material panel to be processed (raw material panel) can be stored in a support plane.

The pallet can e.g. B. be a component of a pallet changer that provides a storage area upstream of the flat bed machine tool. After processing, there may be a large number of cut workpieces on the pallet. The workpieces can be sorted off the pallet manually by an operator or (partially) automatically. For this purpose, the pallet with the material sheet stored on it is typically moved into a sorting position in the storage area and is therefore no longer in the cutting position or in the processing area of the machines. The relative position between the manufactured workpiece and the supporting structures on the pallet can be important both for the manufacturing process and for the sorting process.

The support webs are usually plate-shaped and have support web tips that are spaced evenly apart from one another and form a support plane for a material panel and the cut-out workpieces. Support areas are formed in the area of the support web tips, in which the support webs can be in contact with a material panel mounted in the support plane.

The planning of a nesting (i.e. a nested arrangement) of workpieces to be cut out on the (panel-shaped) material panel is part of the production process in addition to cutting out and sorting. This nesting leads to a specific layout of cutting lines, along which the workpieces are cut out of the material sheet with the help of the cutting beam. Cutting lines include outer and optionally inner contours of workpieces to be cut out. The result of planning a nesting of workpieces is also referred to herein as a nesting plan. A cutting plan can be created on the basis of a nesting plan, in which the order in which the individual workpieces are to be cut out can also be specified.

In the case of flat-bed machine tools, such nesting problems are primarily solved with regard to minimizing the raw material to be used, since the raw material usually makes up a considerable part of the total costs. However, other aspects also affect the overall costs, such as delays in the cutting process or longer downtimes for the flatbed machine tool due to service or repairs. A longer standstill due to service or repairs can be caused in particular by a collision of the sensitive cutting head of the flatbed machine tool with a previously cut and unintentionally "tilted" workpiece if part of the "tilted" workpiece protrudes from the plane of the material panel and with the (the "tilted" workpiece) cutting head collides.

Various approaches for the optimized solution of such nesting problems with a special focus on collision avoidance are known from the prior art. In the DE 10 2012 212 566 A1 against this background - for example - the use of so-called microjoints is discussed in order to prevent unintentional tilting of workpieces with their help. A workpiece is not completely separated from the raw material panel during the cutting process, but remains connected to it via narrow webs, so-called microjoints, and can therefore not tilt. In the course of sorting the workpiece, the microjoints have to be broken; only then can the workpiece be removed from the raw material sheet.

From the DE 10 2018 126 077 A1 a method for determining a nesting plan is known.

From the U.S. 2016/0 318 122 A1 a method for laser-based material processing is known.

One aspect of this disclosure is based on the task of improving the production process with regard to its practical suitability, in particular with regard to the process quality, the process costs and the material utilization. In particular, the object is to enable a specific layout of cutting lines in which the cutting lines can be as close as possible to one another.

At least one of these objects is achieved by a method for compiling a cutting plan according to claim 1, a method for cutting out and sorting according to claim 6, a flat bed machine tool according to claim 8 and computer programs according to claims 9 and 10. Further developments are specified in the dependent claims.

• - Bereitstellen eines Schachtelungsplans, welcher eine Anordnung der Außenkonturen der Mehrzahl von Werkstücken auf einer der Materialtafel zugeordneten Planungstafel umfasst,
• - Zuweisen der Außenkonturen zu jeweils genau einer von mindestens vier Schneidphasen, wobei die Zuweisung derart erfolgt, dass zwei Außenkonturen einer gemeinsamen Schneidphase nicht zueinander benachbart angeordnet sind, wobei zwei Außenkonturen zueinander benachbart angeordnet sind, wenn mindestens zwei Punkte auf einer der zwei Außenkonturen jeweils nicht weiter als einen vorgegebener Nachbarabstand von der anderen der zwei Außenkonturen entfernt sind, und
• - Zusammenstellen des Schneidplans, wobei der Schneidplan für jede Schneidphase die zugeordneten Außenkonturen umfasst.

In one aspect, a method for compiling a cutting plan for cutting out a plurality of workpieces from a plate-shaped sheet of material using a cutting jet emerging from a cutting head, wherein an outer contour and optionally one or more inner contours are traversed with the cutting jet to cut out one of the plurality of workpieces , following steps:

• - providing a nesting plan, which includes an arrangement of the outer contours of the plurality of workpieces on a planning panel assigned to the material panel,
• - Assigning the outer contours to exactly one of at least four cutting phases, the assignment being made in such a way that two outer contours of a common cutting phase are not arranged adjacent to one another, two outer contours being arranged adjacent to one another if at least two points on one of the two outer contours are not are farther than a predetermined neighbor distance from the other of the two outer contours, and
• - Compilation of the cutting plan, the cutting plan including the associated outer contours for each cutting phase.

• - Einlesen eines Schneidplans, der für die Mehrzahl von Werkstücken Außenkonturen umfasst und das Ausschneiden der Mehrzahl von Werkstücken in mindestens vier Schneidphasen untergliedert, wobei die Außenkonturen jeweils einer der mindestens vier Schneidphasen zugeordnet sind und zwei Außenkonturen einer gemeinsamen Schneidphase nicht zueinander benachbart angeordnet sind, wobei zwei Außenkonturen zueinander benachbart angeordnet sind, wenn mindestens zwei Punkte auf einer der zwei Außenkonturen jeweils nicht weiter als einen vorgegebenen Nachbarabstand von der anderen der zwei Außenkonturen entfernt sind,
• - Ausschneiden von Werkstücken, deren Außenkonturen einer gemeinsamen der mindestens vier Schneidphasen zugeordnet sind, und
• - Bereitstellen der in der gemeinsamen Schneidphase ausgeschnittenen Werkstücke zum Absortieren.

In a further aspect, a method for cutting out and sorting out a plurality of workpieces from a plate-shaped material panel using a cutting beam emerging from a cutting head has the following steps:

• - Reading in a cutting plan that includes outer contours for the plurality of workpieces and subdivides the cutting out of the plurality of workpieces into at least four cutting phases, wherein the outer contours are each assigned to one of the at least four cutting phases and two outer contours of a common cutting phase are not arranged adjacent to one another, wherein two outer contours are arranged adjacent to one another if at least two points on one of the two outer contours are no further away than a predetermined neighboring distance from the other of the two outer contours,
• - Cutting out workpieces whose outer contours are associated with a common one of the at least four cutting phases, and
• - Providing the workpieces cut out in the joint cutting phase for sorting.

• - eine in eine Schneidposition und eine Absortierposition bringbare Palette mit Auflagestegen zur Lagerung der plattenförmigen Materialtafel,
• - einen Schneidkopf aus dem der Schneidstrahl austritt und
• - eine Steuereinheit,

wobei die Steuereinheit dazu eingerichtet ist

• - einen Schneidplan einzulesen, der für die Mehrzahl von Werkstücken Außenkonturen umfasst und das Ausschneiden der Mehrzahl von Werkstücken in mindestens vier Schneidphasen untergliedert, wobei die Außenkonturen jeweils einer der mindestens vier zugeordnet sind und zwei Außenkonturen einer gemeinsamen Schneidphase nicht zueinander benachbart angeordnet sind, wobei zwei Außenkonturen zueinander benachbart sind, wenn mindestens zwei Punkte auf einer der zwei Außenkonturen jeweils nicht weiter als einen vorgegebenen Nachbarabstand von der anderen der zwei Außenkonturen entfernt sind,
• - ein Positionieren der Palette in der Schneidposition und ein Ausschneiden von Werkstücken, deren Außenkonturen einer gemeinsamen der mindestens vier Schneidphasen zugeordnet sind, durch Verfahren des Schneidkopfs entlang den Außenkonturen zu veranlassen, und
• - nach Beenden des Ausschneidens der Werkstücke der gemeinsamen der mindestens vier Schneidphasen ein Positionieren der Palette in die Absortierposition zum Absortieren der in der gemeinsamen Schneidphase ausgeschnittenen Werkstücke zu veranlassen.

In a further aspect, a flatbed machine tool for cutting workpieces out of a sheet of material using a cutting jet comprises:

• - a pallet that can be brought into a cutting position and a sorting position with support webs for storing the panel-shaped material panel,
• - a cutting head from which the cutting jet exits and
• - a control unit,

the control unit being set up for this purpose

• - read in a cutting plan that includes outer contours for the plurality of workpieces and subdivides the cutting out of the plurality of workpieces into at least four cutting phases, with the outer contours each being assigned to one of the at least four and two outer contours of a common cutting phase not being arranged adjacent to one another, with two Outer contours are adjacent to each other if at least two points on one of the two outer contours are no further away than a specified neighboring distance from the other of the two outer contours,
• - Positioning the pallet in the cutting position and cutting out workpieces whose outer contours are associated with a common one of the at least four cutting phases are to be brought about by moving the cutting head along the outer contours, and
• - after the end of the cutting of the pieces of the common ones of the at least four cutting phases, cause the pallet to be positioned in the sorting position for the sorting of the pieces cut out in the common cutting phase.

In a further aspect, a computer program comprises instructions which, when the computer program is executed by a computer, cause the computer to carry out the method for compiling a cutting plan.

In a further aspect, a computer program comprises instructions which, when the computer program is executed by a control unit of a flatbed machine tool, cause the control unit to carry out the method for cutting out and sorting a plurality of workpieces.

In some developments, the arrangement of the outer contours of the plurality of workpieces can maintain a minimum distance between the outer contours, with the minimum distance being defined in particular by a material and process-related minimum distance and the neighboring distance being greater than or equal to, in particular equal to, the minimum distance.

• - Ermitteln von zueinander benachbarten Außenkonturen, und
• - Ermitteln eines Bewertungsgraphen, der durch Knoten und Kanten gebildet wird, wobei die Knoten jeweils einer Außenkontur zugeordnet sind und Knoten zueinander benachbarter Außenkonturen durch eine der Kanten miteinander verbunden sind, und
• - wobei das Zuweisen der Außenkonturen zu jeweils genau einer von mindestens vier Schneidphasen auf dem Bewertungsgraphen basiert und insbesondere ein computerimplementierter Algorithmus, der ein Vier-Farben-Theorem implementiert, auf Daten des Bewertungsgraphen zu den Knoten und Kanten angewandt wird.

In some developments, the assignment of the outer contours to exactly one of at least four cutting phases can include:

• - determining mutually adjacent outer contours, and
• - determining an evaluation graph which is formed by nodes and edges, the nodes each being associated with an outer contour and nodes of mutually adjacent outer contours being connected to one another by one of the edges, and
• - wherein the assignment of the outer contours to exactly one of at least four cutting phases is based on the evaluation graph and, in particular, a computer-implemented algorithm that implements a four-color theorem is applied to the nodes and edges of the evaluation graph data.

In some developments, the outer contours can be assigned to exactly one of four cutting phases by means of a four-color theorem, taking into account mutually adjacent outer contours.

• - Zuweisen der Außenkonturen zu jeweils genau einer von vier Schneidphasen insbesondere mittels eines Vier-Farben-Theorems unter Berücksichtigung von zueinander benachbarten Außenkonturen, und daran anschließend
• - Identifizieren von zwei kollisionsgefährdeten Außenkonturen einer gemeinsamen der vier Schneidphasen, wobei zwei Außenkonturen kollisionsgefährdet sind, wenn diese einer gemeinsamen der vier Schneidphasen zugeordnet sind und nicht weiter als einen vorgegebenen Kollisionsabstand voneinander entfernt angeordnet sind, wobei der Kollisionsabstand größer als der Nachbarabstand ist, und
• - Zuweisen einer der zwei kollisionsgefährdeten Außenkonturen zu einer fünften Schneidphase.

In some developments, the outer contours can be assigned to exactly one of five or more cutting phases and include:

• - Assignment of the outer contours to exactly one of four cutting phases, in particular by means of a four-color theorem, taking into account mutually adjacent outer contours, and then thereafter
• - Identifying two outer contours at risk of collision of a common one of the four cutting phases, with two outer contours being at risk of collision if they are associated with one of the common ones of the four cutting phases and are located no further than a predetermined collision distance apart, the collision distance being greater than the neighboring distance, and
• - Assign one of the two outer contours at risk of collision to a fifth cutting phase.

According to the invention, a cutting sequence is created for each of the cutting phases of the cutting plan, which for each of the cutting phases includes a sequence of the outer contours and optionally one or more inner contours belonging to an outer contour.

According to the invention, a meandering path is determined over the planning table for each of the cutting sequences, which determines a method of a cutting head over a plate-shaped material panel, according to which the workpieces of a cutting phase are cut out one after the other when processing the cutting plan.

According to the invention, each outer contour is surrounded by a collision risk area and a travel path between outer contours of one of the cutting phases is determined in such a way that collision risk areas are avoided by outer contours whose associated workpieces have already been cut out in one of the cutting phases.

• - Zusammenstellen eines Schneidplans nach dem zuvor beschriebenen Verfahren zum Zusammenstellen.

In some developments, in the method for cutting out and sorting a plurality of workpieces, the cutting plan can be compiled according to the method for compiling a cutting plan and/or the method for cutting out and sorting a plurality of workpieces can also include:

• - Assemble a cutting plan using the assembling procedure described above.

• - Absortieren der Werkstücke, die in der gemeinsamen Schneidphase ausgeschnitten wurden, und
• - optional nach erfolgtem Absortieren, Ausschneiden von Werkstücken, deren Außenkonturen einer weiteren der mindestens vier Schneidphasen zugeordnet sind, und Bereitstellen der in der weiteren Schneidphase ausgeschnittenen Werkstücke zum Absortieren.

In some developments, the method for cutting out and sorting a plurality of workpieces can also include:

• - sorting of the pieces cut out in the common cutting phase, and
• - optionally after the sorting has taken place, cutting out workpieces whose outer contours are assigned to another of the at least four cutting phases, and preparing the workpieces cut out in the further cutting phase for sorting.

According to the invention, the control unit is provided and set up to execute the method for compiling a cutting plan and/or the method for cutting out and sorting a plurality of workpieces.

The concepts disclosed herein are based on a classification of two workpieces as adjacent workpieces, such as may be done in an algorithmic sequence. In a first step of the classification, based on a neighbor distance criterion, a neighborhood relationship of the workpieces is derived that satisfies two restrictions (1) and (2) from the 4-color theorem. According to the four-color theorem, four colors are always sufficient to color any map in the Euclidean plane in such a way that no two adjacent countries are colored with the same color (so-called four-color problem). The four color theorem holds with the restrictions that (Restriction 1) isolated common points of two countries do not count as a common “boundary” and thus these two countries are not considered to be adjacent, and that (Restriction 2) each country consists of a contiguous area , so there are no exclaves. According to the invention applied to the process of cutting out workpieces from a sheet of material, the countries on the map correspond to the workpieces and the coloring of countries to a common color corresponds to the assignment of workpieces to a common cutting phase. Adjacent lands correspond to workpieces arranged adjacent to each other.

The neighbor distance criterion requires that two outer contours approach each other up to a predetermined neighbor distance. The transferred restriction 1 means that two outer contours are arranged adjacent to one another if the neighboring distance criterion is not only present at one point, but at least two points on one of the two outer contours are no further away from the other of the two outer contours than the neighboring distance. In other words, there is a neighborhood and the neighbor distance criterion is used as long as it is maintained at more than one point on the outer contour. This enforces constraint 1 on an arrangement of workpieces on a sheet of material. The direct proximity of two parts is important here, not the geometric distance; i.e. small parts cannot be "jumped over", otherwise restriction 2 may be violated.

If the adjacency ratio is known, the algorithmic solution to the 4-color problem can be applied, e.g ACM symposium on Theory of Computing, July 1996, pp. 571-575. The result is a categorization of the workpieces into four cutting phases.

Once the categorization is available, the geometric distance can be used to check whether the classification is correct, because restrictions (1) and (2) may be violated. Any existing conflicts - especially with regard to restriction 1 - can be resolved, for example, by recursively inserting additional "colors".

The concepts described here can be advantageous in terms of increasing material utilization (by reducing waste) and workpiece quality. Furthermore, increased process reliability can be achieved, which is associated with reduced production downtimes and reduced service and repair costs.

• 1 eine schematische räumliche Darstellung einer Flachbettwerkzeugmaschine,
• 2 eine schematische Ansicht eines Schachtelungsplans,
• 3 einen vergrößerten Ausschnitt des Schachtelungsplans der 2,
• 4 den vergrößerten Ausschnitt des Schachtelungsplans der 3 mit schematisch eingezeichneten Knoten und Verbindungen,
• 5 eine schematische Darstellung eines Schneidplans,
• 6 ein Flussdiagramm eines Verfahrens zum Zusammenstellen eines Schneidplans,
• 7 ein Flussdiagramm eines Verfahrens zum Ausschneiden und Absortieren einer Mehrzahl von Werkstücken und
• 8 ein Flussdiagramm eines weiteren Ausführungsbeispiels eines Verfahrens zum Ausschneiden und Absortieren einer Mehrzahl von Werkstücken.

Concepts are disclosed herein that allow at least some aspects of the prior art to be improved. In particular, further features and their usefulness result from the following description of embodiments with reference to the figures. From the figures show:

• 1 a schematic spatial representation of a flat bed machine tool,
• 2 a schematic view of a nesting plan,
• 3 an enlarged section of the nesting plan 2 ,
• 4 the enlarged section of the nesting plan 3 with schematically drawn nodes and connections,
• 5 a schematic representation of a cutting plan,
• 6 a flowchart of a method for compiling a cutting plan,
• 7 a flowchart of a method for cutting out and sorting a plurality of workpieces and
• 8th a flowchart of a further embodiment of a method for cutting out and sorting a plurality of workpieces.

Aspects described here are based in part on the knowledge that collisions between the cutting head and workpieces that have already been cut out can be prevented - contrary to current practice - by the sorting not only taking place when all workpieces to be cut out of the material sheet have been cut out. Instead, the workpieces are assigned to different cutting phases and first the workpieces of one cutting phase are cut out and sorted before the workpieces of another cutting phase are cut out (and then sorted).

The work pieces are assigned to the various cutting phases in such a way that a sufficient "safety distance" between two work pieces of the same cutting phase is always guaranteed and thus when cutting out a work piece there is no risk of collision between the cutting head and a previously (in the same cutting phase) cut out tilted workpiece. In other words, collisions can be prevented by assigning the workpieces to a plurality of cutting phases in connection with sequential cutting out and sorting of the workpieces from the individual cutting phases. The cutting phase assignment of the workpieces takes place in such a way that two adjacent workpieces are not assigned to the same cutting phase and all workpieces of a cutting phase are first cut out and sorted before the (following) next cutting phase is started. As a result, when cutting out a workpiece, the cutting head does not travel over (or project beyond) an already cut, adjacent and potentially tilted workpiece and thus does not run the risk of colliding with a tilted workpiece. In this way, collisions can be reliably prevented without z. B. having to increase the minimum distance between adjacent workpieces to such an extent that the cutting head does not run over/overhang any of the adjacent workpieces when cutting out a workpiece. The latter would be associated with reduced material utilization and thus with more waste and higher material costs. In contrast, the concepts disclosed herein allow a sheet of material to be processed with less waste.

Furthermore, the inventors have recognized that the assignment of the workpieces to different cutting phases can in principle be solved with the help of the so-called 4-color theorem or the 4-color theorem, according to which - under certain conditions - four colors are sufficient, any map in of the Euclidean plane so that no two adjacent countries are given the same color - where the countries of the map correspond to the workpieces and the assignment of countries to a common color corresponds to the assignment of workpieces to a common cutting phase. Adjacent countries in this context correspond to workpieces arranged adjacent to one another.

In addition, the aspects described herein are based in part on the knowledge that, particularly in the case of small workpieces, it can be advantageous for reasons of process reliability if these are assigned not just four cutting phases—the mathematically necessary ones—but five or more cutting phases. This is because, even in the case of small workpieces, this allows a sufficiently large distance between two workpieces of a common cutting phase to reliably prevent a collision with the cutting head.

The following is initially based on 1 a flatbed machine tool and the production process of workpieces using this explained. Subsequently, in connection with the 2 until 5 illustrated nesting plan and cutting plan explains the procedure for compiling the cutting plan as well as the procedure for cutting and sorting, which is part of the production process. Finally, the processes discussed are explained with the help of the flow charts according to the 6 until 8th summarized.

In the 1 The schematic flatbed machine tool 1 shown comprises a main housing 3 in which the cutting process is carried out with a cutting beam emerging from a cutting head, here a laser beam as an example. In particular, a focus of the laser beam is guided by a machine controller along predetermined cutting lines arranged in a processing area over a material panel (raw material panel, material) in order to cut a wide variety of workpieces with specific shapes from the material panel. The raw material panel is z. B. an essentially two-dimensionally extending sheet metal, which is processed in a first cutting phase. In the later cutting phase, which is explained in more detail below, the raw material panel is processed, from which the workpieces of the preceding cutting phase(s) have already been cut out and sorted/removed.

The workpieces are each delimited by an outer contour and optionally one or more inner contours.

Furthermore, the flat-bed machine tool 1 includes a pallet changer 5. The pallet changer 5 is designed to receive one or more pallets and to position them during production. A sheet of material to be cut (as a raw material) can be stored on a pallet 5A, moved to a cutting position, and loaded into the main body 3 for cutting. After the cutting process is complete, pallet 5A can be removed as shown in 1 shown, are moved with a cut sheet of material 7 out of the main housing 3 into a sorting position, so that the cut workpieces 9 can be sorted out manually by a worker or (partially) automatically, whereby they are removed from the pallet 5A. The shape of the plate-shaped workpieces 9 is determined by outer contours 27 and inner contours 28 (see FIG 2 ).

How to related to the 2 can recognize shows 1 the sheet of material 7 as it was made available for sorting after the completion of a first cutting phase. When using a pallet changer, a second pallet (not shown in the figures) can be in the cutting position while the cut workpieces are being sorted from one pallet, so that another cutting process can take place there at the same time.

In the main housing 3, the cutting head (laser processing head) from which the cutting beam (laser beam) emerges can be freely positioned in the processing area, so that the laser beam can be guided essentially along any two-dimensional cutting lines over the material panel to be cut. In laser cutting, the laser beam heats the material (metal) along the cutting line until it melts. A gas jet, usually nitrogen or oxygen, usually exits the laser processing head in the area of the laser beam and presses the molten material down and out of the gap that is formed. The material panel 7 can thus be completely severed by the laser beam during cutting.

The laser beam is moved along a cutting line 10 to cut out a workpiece 9 . This usually starts at a puncture point that is outside of the workpiece 9 and then approaches the outer contour of the workpiece 9 in an arc (the so-called first cut). The point at which the cutting line first touches the outer contour of the workpiece is the point at which the cut will later be completed (assuming a continuous cutting process). This point is called pressure point D (see 2 ), since it is the point at which the exiting gas jet exerts pressure on the cut part (workpiece) (detached from the residual material) at the precise moment when it can move freely for the first time. With appropriate distribution of the support web tips under the workpiece, ie the support areas, the gas pressure can lead to a tilting of the workpiece, particularly in the case of thin sheets of material, so that part of the workpiece can potentially protrude from the plane of the metal sheet. The cutting head may collide with the protruding part during a subsequent nearby cutting operation (generally moving operation).

In the exemplary embodiment shown, the pallet 5A has a plurality of support webs 11 running transversely to the direction of insertion and aligned parallel to one another. For example, the support webs 11 have a distance of z. B. 60 mm to each other. The support webs 11 form support areas on which the material panel 7 is placed. The support areas usually form lattice points along the support webs 11 at a distance of z. B. may have 15 mm, with a support bar z. B. has a thickness of 2 mm. Depending on the size and geometry, a workpiece can therefore be positioned so that it tilts, which poses a risk to the cutting head during the cutting process. It is therefore easy to see that, due to storage in localized support areas, process-related risks can affect process reliability and thus increase the risk of rejects and downtime.

1 also shows a camera 13 z. B. is arranged on the main body 3, and the flat bed machine tool 1 controlling control unit 15 (machine control). The camera 13 can be designed, among other things, to capture an image of the pallet 5A, the support webs 11 and support areas 11A and the relative position of the material panel 7 with respect to the pallet 5A (and possibly the support webs 11 and support areas) and is connected to an image evaluation unit of the control unit 15 of the flat bed machine tool 1. The image recordings of the camera 13 can, for. B. can be used to support the sorting process.

As part of the production process, a nesting plan is first proposed as part of the planning of nesting (see 2 and associated description), which represents a process-optimizing arrangement of the workpieces 9 to be cut out on the material panel 7. A cutting plan is then created on the basis of the nesting plan 21 (see 5 and associated description), including an order in which the individual workpieces 9 Aus are to be cut before the cutting and sorting takes place.

An essential boundary condition when nesting workpieces 9 when cutting sheet metal is a minimum distance between the cutting processes to be carried out, i. H. the cutting lines 10. The minimum distance has a direct impact on the amount of material wasted (i.e. the material utilization) and thus on the material costs.

The material and process-related minimum distance represents the distance between the outer contours of adjacent workpieces, which the outer contours must not fall below when nesting. It takes into account the thermal effect of heating the material by cutting along the cutting line and is intended to prevent cutting lines from being too close together and consequently to an increased/too high heat input into the material (with the accompanying disadvantages such as thermal distortion, an influence on the heat dissipation etc.) can occur. The material and process-related minimum distance is thus a parameter that is specific to a material to be cut (type of material and geometry, in particular thickness of the material) and for a cutting process (laser radiation parameters) to take into account a z. B. process-related expansion or warping of the material is specified. Depending on the type of material and the material thickness, the material and process-related minimum distance can be, for example, 3 mm to 20 mm, in particular 5 mm to 12 mm.

When planning and creating a nesting plan, the distance between the outer contours of adjacent workpieces must not fall below the material and process-related minimum distance, otherwise the required quality of the cutting process can no longer be guaranteed when the nesting plan is applied to a material panel.

The application of the method proposed here can enable a reduction in the material and process-related minimum distance, since due to the process, adjacent workpieces or outer contours are not cut in the same cutting phase and thus an increased heat input due to cutting lines that are close together and cut directly one after the other can be avoided. Thus, after a first outer contour has been cut out during a first cutting phase, the material to be cut can cool down again during the sorting phase before an outer contour adjacent to the first outer contour is cut in a further cutting phase. If the concepts according to the invention are used, the nesting can be correspondingly denser.

It is noted that in the prior art, a collision avoidance-related minimum distance can be used, which is typically greater than the material and process-related minimum distance. The minimum distance required to avoid collisions is intended to ensure that when a workpiece is cut out, the cutting head does not collide with a neighboring workpiece if it tilts. If the larger minimum distance required to avoid collisions (instead of the smaller minimum distance required by the material and process) is used as the basis for creating a nesting plan, this leads to larger distances between the outer contours of neighboring workpieces and thus to less favorable material utilization and higher material costs.

The concepts proposed herein make it possible to keep the distance between cutting lines small in consideration of process-related costs and e.g. B. to avoid that this distance has to be (significantly) increased beyond the material and process-related minimum distance to reduce the risk of collision.

2 shows a nesting plan 21, as in the context of a planning board 25 z. B. can be generated with the help of an evolutionary algorithm by the control unit 15 of the flat bed machine tool or a separate computer unit under the condition of a material and process-related minimum distance Min. The planning board 25 is transferred to the material board 7 for the cutting process in such a way that corresponding geometry data of the planning board 25 correspond to or lie within the processing area provided by the flatbed machine tool 1 for a workpiece board 7 . In the present example, a rectangular planning board 25 is used, which is to be applied to a correspondingly rectangular-shaped material board.

The nesting plan 21 shows a non-overlapping arrangement of outer contours 27 and inner contours 28 of a plurality of workpieces 9 on the two-dimensional planning board 25. The nesting plan 21 thus defines the vicinity of the workpieces 9. Two outer contours 27 are arranged at least the material and process-related minimum distance Min apart from each other (see 3 ).

The nesting plan 21, ie the non-overlapping arrangement of the outer and inner contours, is created in a planning phase preceding the cutting process and within the scope of the disclosed method for assembling a cutting plan 23 is provided. The nesting plan 21 can be created, for example, by the control unit 15 of the flatbed machine tool 1, e.g. B. if in the planning z. B. currently recorded position data flow, or by an independent planning unit (an independent computer) with appropriate computing and storage capacity.

The control unit 15 of the flatbed machine tool 1 is set up to enable a method for compiling a cutting plan for cutting out a plurality of workpieces (9) from a panel-shaped material panel. The calculations required for this, for example for the creation of the evaluation graph and its analysis according to an algorithmic solution of the 4-color problem, can be carried out with the processor of the control unit 15, for example. The control unit 15 can be embodied as a PC, computing node or similar suitable hardware and in particular as part of a cross-system controller that also controls the flatbed machine tool 1 for processing flat material and also plans nesting of workpieces to be produced. The control unit 15 can thus be designed as part of a higher-level or local control system of the flatbed machine tool 1 or as a separate unit. The control unit 15 is set up in particular to carry out/control the methods disclosed herein during real-time operation of the flatbed machine tool 1 . For this purpose, the underlying computing system of the control unit 15 has, for example, digital processor systems with microprocessor circuits having data inputs and control outputs, as well as databases that are operated according to computer-readable instructions stored on a computer-readable medium. The instructions include, for example, computer routines of an algorithmic solution to the 4 color problem. The control unit 15 can provide high computing power for real-time support. It can also have a long-term (non-volatile) memory for storing the program instructions as well as a very fast short-term (volatile) memory for (temporarily) storing acquired data and data sets generated while the method is being carried out.

The method for compiling a cutting plan 23 begins with the provision of the nesting plan 21. Based on the nesting plan 21 provided, all outer contours 27 and inner contours 28 are assigned to exactly one of four cutting phases I, II, III, IV. The assignment is made in such a way that two outer contours 27 of a common cutting phase I, II, III or IV are not arranged adjacent to one another. The assignment of the outer contours 27 and inner contours 28 and the associated workpieces 9 to the individual cutting phases I, II, III, IV is in the 2 until 4 indicated by the different hatching of the workpieces 9: unhatched workpieces 9 are assigned to cutting phase I, workpieces hatched from top right to bottom left to cutting phase II, workpieces hatched from top left to bottom right to cutting phase III and horizontally hatched workpieces to cutting phase IV /assigned.

Inner contours belong to cuts that each delimit an inner area of a workpiece and thus in particular an area of the raw material sheet (inner contour waste). The inner contours 28 in the 2 until 4 Workpieces 9 shown lead to inner contour cuts, which because of their small size - can fall directly out of the raw material panel - compared to the distances between the individual support webs / support areas of a pallet; a dangerous tilting of the inner contour cuts and a potential collision of these with the cutting head can thus be (largely) prevented. The inner contour offcuts can also be cut up using the cutting jet in order to further reduce the size and thus to further promote the falling out of the raw material panel. The inner contours 28 in the 2 until 4 Workpieces 9 shown are each associated with the cutting phase, which is also associated with the associated outer contour 27 of the workpiece. Usually, inner contour cuts and possibly the cutting of the inner contour cuts are carried out before the associated outer contour.

It is noted that in the case of an inner contour that would lead to an inner contour cut with a size (e.g. larger than a DIN A6 sheet) so that it can no longer be guaranteed that it will fall out of the raw material sheet, it can be useful to Assign inner contour to a cutting phase, which is carried out before the cutting phase of the associated outer contour.

The fact that two workpieces (or the respective outer contours) are arranged adjacent to one another or not is included in the concepts proposed here. Two workpieces or the respective outer contours are considered to be “arranged adjacent to one another” if at least two points on one of the two outer contours are no further away than a specified neighboring distance from the other of the two outer contours.

To clarify the neighborhood relationship is on the enlarged section A of 3 according to the nesting plan 21 2 referred. Two points N1 and N2 can be seen on the outer contour 27.I', which are each arranged at a distance D_N from the outer contour 27.III''' at a distance D_N. The two outer contours 27.I' and 27.III''' are therefore arranged adjacent to one another and assigned to different cutting phases accordingly. The neighboring distance D_N is selected in such a way that it corresponds to the minimum distance Min.

On the other hand, the outer contour 27.II' is not arranged adjacent to the outer contour 27.I'. This is because there are no two points on the outer contour 27.I' that are no further away from the outer contour 27.II' than the neighboring distance D_N. The points N3 and N4, which lie on the outer contour of 27.I' and come closest to the outer contour 27.II', are each further away from the outer contour 27.II' than the neighboring distance D_N. The outer contour 27.I'' is likewise not adjacent to the outer contour 27.I'. Correspondingly, the outer contour 27.I'' and the outer contour 27.II' with respect to the cutting phase of the outer contour 27.I' can be assigned to the same or a different cutting phase.

The outer contour 27.II'' is likewise not adjacent to the outer contour 27.I'. It is true that there is a (single) point N5 on the outer contour 27.I', which is arranged at a distance D_N from the outer contour 27.II''. However - because of the radius of the outer contour 27.11" - there is no other point on the outer contour 27.1' for which this also applies. Accordingly, the two outer contours 27.1' and 27.11" are not arranged adjacent to one another in the present sense and can have the same cutting phase or different cutting phases (as in 3 shown) are assigned.

The neighboring distance D_N is expediently chosen in such a way that it corresponds to the minimum distance Min. However, the neighboring distance D_N can also be selected to be greater than the minimum distance Min. If the neighboring distance D_N was chosen to be greater than the minimum distance Min, however, in the event that two outer contours have only a single pair of points that are at a minimum distance from each other, a map can result in the sense of the 4-color theorem, which against restriction (1 ) from the 4-color theorem violates. The neighbor distance D_N will thus usually match the minimum distance Min.

The assignment of the outer contours 27 and the inner contours 28 and thus the associated workpieces 9 to four cutting phases I, II, III, IV can be done using the mathematical four-color theorem (four-color theorem), which says that - under certain conditions, which are fulfilled in the present case - four colors (here the cutting phases) are always sufficient to color any map in the Euclidean plane (here the planning board) in such a way that no two adjacent countries (here the workpieces) get the same color. The outer contours are understood as "countries" and two outer contours are considered "adjacent" to each other (considered) if they are "neighboring" according to the above statements. The different colors correspond in z. B. 2 the different cutting phases I, II, III, IV.

The assignment task can be solved numerically using so-called graph theory, as described by Neil Robertson, Daniel P. Sanders, Paul Seymour and Robin Thomas, for example, in the paper "Efficiently four-coloring planar graphs", STOC '96: Proceedings of the twenty- eighth annual ACM symposium on Theory of Computing, July 1996, pp. 571-575.

1. a. Wenn die Anzahl der Knoten n von G kleiner gleich 4 ist, ist das Problem trivial.
2. b. Falls G ein Face mit mindestens Grad 4 hat, gibt es zwei nicht-benachbarte Knoten x, y, die mit das Face umschließen. Diese werden als z zusammengefasst, wodurch ein neuer Graph H entsteht. Dieses Vorgehen wird rekursiv aufgerufen, bis die Lösung trivial ist. Die Knoten werden dann in G so eingefärbt, wie es in H gewesen wäre (x, y erhalten die Farbe von z).
3. c. Falls G einen Knoten x mit Grad kleiner gleich 4 hat, wird dieser von einem k-ring umschlossen. Dieser Fall wird mit einer k-ring-Analyse behandelt.
4. d. Sonst hat G mindestens den Grad 5. Hier lässt sich der Graph entweder so zerlegen, dass ein k-ring auftritt, der wieder in der k-ring Analyse behandelt wird. Sonst lässt sich G so vereinfachen (Knoten zusammenlegen), dass eine Kempe-Kette entsteht, für die eine korrekte Färbung angegeben werden kann. Dies kann wie oben rückgängig gemacht werden, sodass zusammengelegte Knoten dieselbe Farbe haben.
5. e. K-ring Analyse: Ein Ring R wird von außen durch einen Sub-Graph E von G und von innen durch den Sub-Graph I von G umschlossen. Ein Graph H1 wird als G ohne E definiert. Es lässt sich in diesem Fall eine Färbung von G finden. Entsprechend kann H2 als G ohne I definiert werden. Diese beiden Färbungen von H1 und H2 können dann so angeordnet werden, dass sie eine korrekte Färbung von R mit einfachen Operationen ermöglichen. (Siehe auch den Beweis aus G.D. Birkhoff, „The reducability of maps“, American Journal of Mathematics 35, 1913, Seiten 114-128.

In the following, an attempt is made to briefly summarize the algorithm for the 4-color theorem, with the algorithm from Robertson et al., 1996 being described in detail in the publication and, in case of doubt, the procedure from this publication being meant. A graph G (herein also referred to as an evaluation graph) consists of nodes and edges (herein also referred to as a connection) and encloses several areas (“face”). The degree of a face denotes the number of nodes that enclose this face:

1. a. If the number of nodes n of G is less than or equal to 4, the problem is trivial.
2. b. If G has a face of at least degree 4, then there are two non-adjacent vertices x, y that enclose the face. These are combined as z, resulting in a new graph H. This procedure is called recursively until the solution is trivial. The vertices are then colored in G as they would have been in H (x,y get the color of z).
3. c. If G has a vertex x with degree less than or equal to 4, it is enclosed by a k-ring. This case is treated with a k-ring analysis.
4. i.e. Otherwise G has at least degree 5. Here the graph can either be decomposed in such a way that a k-ring occurs, which is again treated in the k-ring analysis. Otherwise G can be simplified (joining the nodes) in such a way that a Kempe chain results, for which a correct coloring can be specified. This can as above, so that merged nodes have the same color.
5. e. K-ring analysis: A ring R is enclosed by a subgraph E of G from the outside and by the subgraph I of G from the inside. A graph H1 is defined as G without E. In this case a coloring of G can be found. Similarly, H2 can be defined as G without I. These two colorings of H1 and H2 can then be arranged to allow correct coloring of R with simple operations. (See also the proof from GD Birkhoff, "The reducability of maps", American Journal of Mathematics 35, 1913, pages 114-128.

As in 4 For this purpose, the nesting plan 21 is indicated as being converted into a planar graph (evaluation graph) in that a node 29 is assigned to each outer contour 27 (and thus to each workpiece 9). Furthermore, in each case two nodes 29, to which mutually adjacent outer contours 27 are assigned (eg 27.I' and 27.III'''), are connected to one another by a connection (also referred to as an edge) 30. Furthermore, two nodes 29 to which non-adjacent outer contours 27 are assigned (e.g. 27.I' and 27.II'', and 27.I' and 27.II') are not connected by a connection, which is shown in 4 is indicated as an example for the outer contours 27.I' and 27.II'' and 27.I' and 27.II' by a dashed and crossed-out line between these two outer contours.

According to graph theory, a maximum of n ² elementary operations are necessary for the assignment of n nodes 29 (and thus the associated outer contours 27 and workpieces 9) to the four colors (or the four cutting phases).

As a result, the outer contours 27 are each assigned to exactly one of four cutting phases I, II, III, IV, with the assignment being made in such a way that two outer contours 27 of a common cutting phase I, II, III, IV are not arranged adjacent to one another.

For reasons of process reliability, it can make sense, especially with small workpieces, not only to assign them to four cutting phases I, II, III, IV - the mathematically necessary - but to five or more cutting phases. The background to this finding is that it can happen, especially with small workpieces, that two workpieces of a common cutting phase (although they are not arranged adjacent to one another) are arranged so close together that the cutting head during the cutting out of one of the two workpieces with the one previously cut out other of the two workpieces collides. The risk of collision can be prevented in this context by the workpieces z. B. be assigned to one of four (mathematically necessary) cutting phases according to the 4-color theorem described above. Subsequently, workpieces that are assigned to one of the four cutting phases and from which there is a risk of collision (workpieces at risk of collision) - because they are not arranged further than a predetermined collision distance apart - are assigned to different cutting phases by assigning one of the workpieces at risk of collision to another, fifth cutting phase is assigned. For this purpose, two outer contours at risk of collision of a common one of the four cutting phases are first identified and then one of the two outer contours at risk of collision is assigned to a fifth cutting phase. In particular, all pairs of workpieces in a cutting phase can be checked with regard to the risk of collision. Two outer contours are not arranged further apart from each other than the specified collision distance if a smallest distance between the two outer contours is less than or equal to the collision distance.

If it is subsequently determined that there is a risk of collision from two workpieces that have been assigned to the fifth cutting phase, one of the two workpieces is assigned to a sixth cutting phase and the risk of collision is thus eliminated. This procedure can be continued accordingly iteratively for the sixth and any further cutting phases.

The specified collision distance within which there is a potential risk of collision is determined, among other things, by the dimensions of the cutting head (cutting nozzle), a possible tilting height of one of the workpieces and the type of storage of the material panel on the pallet. The collision distance can be specified, for example, in the range from 5 mm to 50 mm, in particular in the range from 7 mm to 35 mm.

In 3 a collision risk area K spanned by the collision distance D_K around the outer contour 27.I' is drawn in as an example with a dashed line. Assuming that the outer contours 27.I' and 27.II'' had been assigned to a common cutting phase (which would have been entirely permissible since these two outer contours are not considered to be adjacent to one another according to the above), the outer contours 27.I' would and 27.II'' are considered to be outer contours at risk of collision, since they are arranged less than the specified collision distance from one another. (The outer contour 27.II' protrudes into the collision risk area K of the outer contour 27.I'.) By assigning one of the two collision risk outer contours to a fifth cutting phase V (see 5 ), the outlined (hypothetical) risk of collision could be averted.

It is noted that in the event that the outer contours 27.I' and 27.II'' should belong to a common cutting phase, an operator could alternatively have changed the cutting plan such that he removed the workpiece 27.II'' from the collision risk area K (up in the drawing plane) pushes out.

Based on the assignment of the outer contours 27 to the four cutting phases, a - as in 5 cutting plan 23 compiled in a schematic-structural manner. For each of the cutting phases I, II, III, IV, the cutting plan 23 includes the assigned outer contours 27, a sequence 23R in which the outer contours 27 are to be cut out within the assigned cutting phase I, II, III, IV, and also the individual outer contours 27 associated position data P1, P2, P3 and detail data D1, D2, D3. The position data P1, P2, P3 can, for example, define the position, the orientation and/or the course of the assigned outer contour 27. The detailed data D1, D2, D3 can, for example, define the section of the associated outer contour 27 in more detail. In 5 only the first three entries are shown for each cutting phase for reasons of clarity; the points indicate that the individual cutting phases can, of course, also include more than three outer contours.

The sequence 23R of the outer contours is determined in such a way that the workpieces 9 of a cutting phase I, II, III, IV are cut out one after the other when the cutting plan 23 is processed along a meandering path of the cutting head over the planning board 25 . In 2 For this purpose, a travel path WI provided for the cutting phase I is drawn in as a roughly schematic broken line.

The traverse path of a cutting phase is generally determined in such a way that a collision of the cutting head with a workpiece that has already been cut out (and not yet sorted) is avoided within the cutting phase. This can be achieved in that each outer contour 27 has a collision risk area K (defined by the collision distance) surrounding it (cf. 3 ) is assigned and the travel path between outer contours within a cutting phase is determined in such a way that the collision risk areas K of outer contours 27, whose associated workpieces 9 have already been cut out in the respective cutting phase I, II, III, IV, are bypassed by the travel path W and are not crossed (please refer 2 ). This can be achieved by the cutting head, after the pressure point D has been reached, i.e. the cutting of a workpiece has been completed, being moved directly away from the collision risk area K of the workpiece in question and not entering the collision risk area of the workpiece again in the further course of the relevant cutting phase overruns/overlooks/crosses. The pressure point D for cutting out a first workpiece 9 is expediently chosen such that it is as close as possible to a second workpiece, which is to be cut out after the first workpiece in the same cutting phase. For reasons of process efficiency, it can be useful if the cutting head travels the shortest way from the pressure point D of the first workpiece (after the first workpiece has been cut out) to the pressure point D of the second workpiece, and the travel path is thus designed as a direct connection between the two pressure points D. However, in order to prevent the cutting head from crossing the collision risk area K of a workpiece that has already been cut out, the travel path can be guided around the collision risk area K and thus a longer distance can be accepted - see travel path WI between the pressure points D' and D'' in 2 .

It is noted that the traverse path W.I does not take internal contours into account. These can be processed for each of the workpieces before cutting the respective outer contour.

The method described so far for compiling the cutting plan 23 can then be directly followed by the method for cutting out and sorting the workpieces described below.

For this purpose, the cutting plan 23, which subdivides the cutting out of the workpieces into several cutting phases, is read in. The pallet 5A with the material panel 7 stored on it is then moved into the cutting position and the workpieces 9, which are assigned to the first cutting phase I or their outer contours 27 to the first cutting phase I, are moved in the sequence 23R specified by the cutting plan 23 along the traversing path W.I cut out.

After all workpieces 9 of the first cutting phase I have been cut out (and thus the first cutting phase I is completed), these workpieces 9 are cut as in 1 shown provided for sorting by moving the pallet 5A with the sheet of material 7 stored thereon to the sorting position. The sorting of the Cut workpieces 9, ie the removal of the cut workpieces from the pallet 5A, can be done manually by a worker or (partially) automatically (e.g. by means of a robot).

After the complete sorting of all workpieces 9, which are assigned to the first cutting phase I, the pallet 5A with the material panel 7 stored thereon is moved back into the cutting position. Workpieces 9, which are assigned to the second cutting phase II, are now cut out. After completion of the second cutting phase II, the workpieces cut out in the cutting phase II are made available for sorting by the pallet 5A together with the material panel 7 being moved again into the sorting position. After the workpieces 9 of the second cutting phase II have been sorted, the last-mentioned steps are then repeated for the third and fourth cutting phase until finally all workpieces 9 are cut out and sorted according to the nesting plan 21 and the production process is thus concluded.

• - Bereitstellen 100 des Schachtelungsplans 21, insbesondere Einlesen des Schachtelungsplans 21 in einen Prozessor der Steuerungseinheit 15,
• - Zuweisen 200 der Außenkonturen 27 zu jeweils genau einer von mindestens vier Schneidphasen I, II, III, IV, wobei die Zuweisung derart erfolgt, dass zwei Außenkonturen 27 einer gemeinsamen Schneidphase I, II, III, IV nicht zueinander benachbart angeordnet sind, insbesondere ansteuern des Prozessors zum Durchführen eines Algorithmus' für die Zuweisung der Außenkonturen zu den Schneidphasen, und
• - Zusammenstellen 300 des Schneidplans 23, insbesondere durch Ansteuern des Prozessors zur Zusammenstellung der mit dem Algorithmus gewonnenen Daten.

Accordingly, it can be summarized that the method for compiling the cutting plan 23 as shown in the flow chart according to 6 outlined, includes the following steps explained above:

• - Providing 100 the nesting plan 21, in particular reading the nesting plan 21 into a processor of the control unit 15,
• - Allocation 200 of the outer contours 27 to exactly one of at least four cutting phases I, II, III, IV, the allocation being made in such a way that two outer contours 27 of a common cutting phase I, II, III, IV are not arranged adjacent to one another, in particular are controlled the processor for executing an algorithm for assigning the external contours to the cutting phases, and
• - Compilation 300 of the cutting plan 23, in particular by controlling the processor for compiling the data obtained with the algorithm.

• - Einlesen 400 des Schneidplans 23, insbesondere in die Steuerungseinheit der Werkzeugmaschine,
• - Ausschneiden 500 von Werkstücken 9, deren Außenkonturen 27 einer gemeinsamen der vier Schneidphasen I, II, III, IV zugeordnet sind mit der Werkzeugmaschine, und
• - Bereitstellen 600 der in der gemeinsamen Schneidphase I, II, III, IV ausgeschnittenen Werkstücke zum Absortieren, insbesondere durch Bringen einer Palette in die Absortierposition,
• - Absortieren 700 der Werkstücke 9, die in der gemeinsamen Schneidphase I, II, III, IV ausgeschnitten wurden,
• - Ausschneiden 800 von Werkstücken 9, deren Außenkonturen 27 einer weiteren der vier Schneidphasen I, II, III, IV zugeordnet sind mit der Werkzeugmaschine, und
• - Bereitstellen 900 der in der weiteren Schneidphase I, II, III, IV ausgeschnittenen Werkstücke 9 zum Absortieren, insbesondere durch Bringen der Palette in die Absortierposition.

Furthermore, the above-described method for cutting out and sorting of workpieces, as shown in the flow charts according to 7 and 8th outlined the following steps:

• - Reading in 400 the cutting plan 23, in particular in the control unit of the machine tool,
• - Cutting out 500 of workpieces 9, whose outer contours 27 are assigned to a common one of the four cutting phases I, II, III, IV with the machine tool, and
• - Providing 600 of the workpieces cut out in the common cutting phase I, II, III, IV for sorting, in particular by bringing a pallet into the sorting position,
• - Sorting 700 the workpieces 9 cut out in the common cutting phase I, II, III, IV,
• - Cutting out 800 of workpieces 9, whose outer contours 27 are assigned to another of the four cutting phases I, II, III, IV with the machine tool, and
• - Preparing 900 the workpieces 9 cut out in the further cutting phase I, II, III, IV for sorting, in particular by bringing the pallet into the sorting position.

The method for compiling the cutting plan 23 can be carried out by the control unit 15 of the flat bed machine tool 1 or by a separate processing unit (computer). In this case, in particular, a computer program comprising commands causes the method to be executed by the control unit 15 or the separate processing unit.

The method for cutting out and sorting can - with the exception of step 700, the sorting, which may require the manual intervention of a worker - also be carried out by the control unit 15 of the flat bed machine tool 1, with a computer program including instructions being used here in particular to carry out the method the control unit 15 causes.

The concepts disclosed here thus contribute on the one hand to making it possible to avoid collisions between the cutting head of the flat-bed machine tool 1 and tilted workpieces 9 . On the other hand, they enable a high degree of utilization and, as a result, little waste through the implementation of nesting plans, in which the minimum distance between the workpieces is preferably only determined by the material and process-related minimum distance, and is not further increased due to considerations to reduce the risk of collision got to.

It is explicitly emphasized that all features disclosed in the description and/or the claims are to be considered separately and independently of each other for the purpose of original disclosure as well as for the purpose of limiting the claimed invention independently of the feature combinations nations are to be considered in the embodiments and/or the claims. It is explicitly stated that all indications of ranges or groups of units disclose every possible intermediate value or subgroup of units for the purpose of original disclosure as well as for the purpose of limiting the claimed invention, in particular also as a limit of a range indication.

Claims (10)

Method for compiling a cutting plan (23) for cutting out a plurality of workpieces (9) from a sheet-like material panel (7) with the aid of a cutting beam emerging from a cutting head, wherein for cutting out one of the plurality of workpieces (9) an outer contour (27) and optionally one or more inner contours (28) can be traced with the cutting jet, with the following steps: - Providing (100) a nesting plan (21) which comprises an arrangement of the outer contours (27) of the plurality of workpieces (9) on a planning board (25) assigned to the material board (7), - Assigning (200) the outer contours (27) to exactly one of at least four cutting phases (I, II, III, IV), the assignment being made in such a way that two outer contours (27) of a common cutting phase (I, II, III, IV) are not arranged adjacent to one another, with two outer contours (27) being arranged adjacent to one another if at least two points (N1, N2) on one of the two outer contours are no further than a predetermined neighboring distance (D_N) from the other of the two outer contours ( 27) are removed, and - Compilation (300) of the cutting plan (23), wherein the cutting plan (23) for each cutting phase (I, II, III, IV) includes the associated outer contours (27), - Creation of a cutting sequence (23R) for each of the cutting phases (I, II, III, IV) of the cutting plan (23), which for each of the cutting phases (I, II, III, IV) a sequence of the outer contours (27) and optionally a or comprises several inner contours (28) belonging to an outer contour (27), - Determination of a meandering travel path (W) over the planning board (25) for each of the cutting sequences (23R), which determines a travel of the cutting head over the plate-shaped material panel (7), according to which the workpieces (9) of a cutting phase (I, II, III, IV) are cut out one after the other when processing the cutting plan (23), each outer contour (27) being surrounded by a collision risk area (K) and the travel path (W) between the outer contours (27) of one of the cutting phases (I, II, III , IV) is determined in such a way that collision risk areas (K) of outer contours (27) whose associated workpieces (9) have already been cut out in one of the cutting phases (I, II, III, IV) are avoided. procedure after claim 1 , wherein the arrangement of the outer contours (27) of the plurality of workpieces (9) maintains a minimum distance (Min) between the outer contours (27), the minimum distance (Min) being defined in particular by a material and process-related minimum distance and the neighboring distance (D_N ) is greater than or equal to, in particular equal to, the minimum distance (Min). Method according to one of the preceding claims, wherein the assignment (200) of the outer contours (27) to exactly one of at least four cutting phases (I, II, III, IV) comprises: - determining mutually adjacent outer contours (27), and - Determination of an evaluation graph, which is formed by nodes (29) and edges (30), the nodes (29) each being associated with an outer contour (27) and nodes (29) of mutually adjacent outer contours (27) through one of the edges (30 ) are connected to each other, and wherein the assignment of the outer contours (27) to exactly one of at least four cutting phases (I, II, III, IV) is based on the evaluation graph and in particular a computer-implemented algorithm that implements a four-color theorem, is applied to evaluation graph data on nodes (29) and edges (30). Method according to one of the preceding claims, wherein the outer contours are assigned to exactly one of four cutting phases (I, II, III, IV) using a four-color theorem, taking into account mutually adjacent outer contours (27). Procedure according to one of Claims 1 until 3 , wherein the assignment of the outer contours (27) to exactly one of five or more cutting phases (I, II, III, IV) takes place and comprises: - assignment of the outer contours (27) to exactly one of four cutting phases (I, II, III, IV) in particular by means of a four-color theorem, taking into account mutually adjacent outer contours (27), and then - identifying two outer contours (27) at risk of collision of a common one of the four cutting phases (I, II, III, IV), wherein two outer contours (27) are at risk of collision if they are assigned to one of the four cutting phases (I, II, III, IV) and are not located further apart than a predetermined collision distance (D_K), the collision distance (D_K) being greater than the neighbor distance (D_N), and - Assigning one of the two outer contours (27) at risk of collision to a fifth cutting phase (V). Method for cutting out and sorting a plurality of workpieces (9) from a plate-shaped material panel (7) using a cutting beam emerging from a cutting head, with the following steps: - reading in (400) a cutting plan (23) which is for the plurality of workpieces ( 9) includes outer contours (27) and the cutting out of the plurality of workpieces (9) is subdivided into at least four cutting phases (I, II, III, IV), wherein the outer contours (27) each represent one of the at least four cutting phases (I, II, III , IV) and two outer contours (27) of a common cutting phase (I, II, III, IV) are not arranged adjacent to one another, with two outer contours (27) being arranged adjacent to one another if at least two points (N1, N2) on one of the two outer contours is no further away than a predetermined neighboring distance (D_N) from the other of the two outer contours (27), - cutting out (500) workpieces (9), whose outer contour n (27) are assigned to a common one of the at least four cutting phases (I, II, III, IV), and - providing (600) the workpieces (9) cut out in the common cutting phase (I, II, III, IV) for sorting, wherein the cutting plan (23) by a method according to any one of Claims 1 until 5 was compiled. procedure after claim 6 also with: - Sorting (700) the workpieces (9) that were cut out in the common cutting phase (I, II, III, IV), and - optionally after the sorting (700) has taken place, cutting out (800) workpieces (9) , whose outer contours (27) are assigned to another of the at least four cutting phases (I, II, III, IV), and providing (900) the workpieces (9) cut out in the further cutting phase (I, II, III, IV) for sorting . Flat-bed machine tool (1) for cutting out workpieces (9) from a sheet of material (7) using a cutting jet, comprising: - a pallet (5A) that can be brought into a cutting position and a sorting position and has support webs (11) for storing the plate-shaped sheet of material (7) , - a cutting head from which the cutting beam emerges and - a control unit (15), the control unit (15) being set up to - read in a cutting plan (23) which comprises outer contours (27) for the plurality of workpieces (9) and that Cutting out the plurality of workpieces (9) divided into at least four cutting phases (I, II, III, IV), wherein the outer contours (27) are each assigned to one of the at least four cutting phases (I, II, III, IV) and two outer contours ( 27) of a common cutting phase (I, II, III, IV) are not arranged adjacent to each other, with two outer contours (I, II, III, IV) being adjacent to each other if at least two points (N1, N2) on a he of the two outer contours are no further away than a predetermined neighboring distance (D_N) from the other of the two outer contours (27), - positioning the pallet (5A) in the cutting position and cutting out workpieces (9) whose outer contours (27 ) associated with one of the at least four cutting phases (I, II, III, IV) by moving the cutting head along the outer contours (27), and - after the workpieces (9) have been cut out, the common one of the at least four cutting phases ( I, II, III, IV) positioning the pallet (5A) in the sorting position for sorting the workpieces (9) cut out in the common cutting phase (I, II, III, IV), the control unit (15) being provided for this purpose and set up is the method for compiling a cutting plan according to one of Claims 1 until 5 and/or the method according to any one of Claims 6 until 7 to execute. Computer program, comprising instructions which, when the computer program is executed by a computer, cause the latter to carry out the method according to one of Claims 1 until 5 to execute. Computer program comprising instructions which, when the computer program is executed by a control unit (15) of a flatbed machine tool (1), causes the control unit (15) to carry out the method according to one of Claims 6 or 7 to execute.

Images